[Comparison of patients with paroxysmal junctional tachycardia and syncope with those without syncope]

INTRODUCTION

The purpose of the study was to determine the possible mechanisms of presyncope in patients who have paroxysmal junctional tachycardias (PJT) and a normal surface ECG between tachycardias.

METHODS

Among 419 patients consecutively recruited for PJT, aged from 10 to 88 years (47+/-19), 78 of them had presented at least one syncope; they had a normal ECG in sinus rhythm. Transesophageal programmed atrial stimulation was performed using one and two atrial extrastimuli delivered in control state and if necessary after infusion of 20-30 microg of isoproterenol; arterial blood pressure was monitored; vagal maneuvers and tilt test (n=25) were performed; echocardiogram was systematic.

RESULTS

Age, sex, method of induction, tachycardia mechanism and the mean heart rate in tachycardia were similar in patients with and without syncope. Syncope was related to a vagal reaction induced by the PJT in 31 patients, to a fast rate during PJT in 15 patients, to a sinus node dysfunction in six patients, to a coronary ischemia in five patients, to a tetany induced by PJT in three patients, to an advanced age in three patients, to multiple causes in three patients and remained unexplained in eight patients. Radiofrequency ablation of reentrant circuit, performed in 28 patients, suppressed syncope in 26 of them.

CONCLUSION

Presyncope or syncope occurred in 18% of patients who had a history of paroxysmal junctional tachycardia. Several mechanisms were implicated; the most frequent causes were coronary ischemia or sick sinus syndrome in old patients, vasovagal reaction or fast rate in tachycardia or tetany in patients of all ages.

Diagnostic and therapeutic trajectory of cluster headache patients in Flanders

OBJECTIVE

A fraction of cluster headache (CH) patients face diagnostic delay, misdiagnosis, undertreatment and mismanagement. Specific data for Flanders are warranted.

METHODS

Data on CH characteristics, diagnostic process and treatment history were gathered using a self-administered questionnaire with 90 items in CH patients that presented to 4 neurology outpatient clinics.

RESULTS

Data for 85 patients (77 men) with a mean age of 44 years (range 23-69) were analysed. 79% suffered from episodic CH and 21% from chronic CH. A mean diagnostic delay of 44 months was reported. 31% of patients had to wait more than 4 years for the CH diagnosis. 52% of patients consulted at least 3 physicians prior to CH diagnosis. Most common misdiagnoses were migraine (45%), sinusitis (23%), tooth/jaw problems (23%), tension-type headache (16%) and trigeminal neuralgia (16%). A significant percentage of patients had never received access to injectable sumatriptan (26%) or oxygen (31%). Most prescribed preventative drugs after the CH diagnosis were verapamil (82%), lithium (35%), methysergide (31%) and topiramate (22%). Despite the CH diagnosis, ineffective preventatives were still used in some, including propranolol (12%), amitriptyline (9%) and carbamazepine (12%). 31% of patients had undergone invasive therapy prior to CH diagnosis, including dental procedures (21%) and sinus surgery (10%).

CONCLUSION

Despite the obvious methodological limitations of this study, the need for better medical education on CH is evident to optimize CH management in Flanders.

Comparison of epirubicin and doxorubicin cardiotoxicity induced by low doses: evolution of the diastolic and systolic parameters studied by radionuclide angiography

BACKGROUND

Previous studies have demonstrated that epirubicin (EPI) has a lower propensity to produce cardiotoxic effects than doxorubicin (DXR) at high doses.

HYPOTHESIS

The aim of the study was to compare the cardiotoxicity induced by low doses of EPI and DXR in patients before and 1 month after the end of chemotherapy.

METHOD

In a prospective study, 99 patients with a mean age of 51 +/- 12 years and without cardiac disease were studied before and 1 month after the end of chemotherapy. Group 1 included 38 patients receiving 246 +/- 96 mg/m2 of DXR and Group 2 included 61 patients receiving EPI with and equivalent dose of 219 +/- 92 mg/m2 of DXR. Ejection fraction (EF) of the left ventricle (LV), peak ejection rate (PER), and peak filling rate (PFR) [expressed in end-diastolic volume/s (EDV/s)] were evaluated by gated radionuclide angiography; PFR/PER were also calculated.

RESULTS

Moderate and similar alterations of left ventricular ejection fraction were shown for low doses of anthracyclines. The EF of the LV decreased from 57 +/- 6% to 54 +/- 6% for DXR group (Group 1) (p = 0.005), and from 58 +/- 5% to 55 +/- 5% for the EPI group (Group 2)(p = 0.001). The PER of the left ventricle fell from 3.08 +/- 0.46 EDV/s to 2.79 +/- 0.49 in Group 1 (p = 0.004) and from 2.98 +/- 0.50 to 2.73 +/- 0.34 EDV/s in Group 2 (p = 0.001). In contrast, no significant alteration of PFR appeared in Group 2 (from 2.72 +/- 0.51 to 2.62 +/- 0.41 EDV/s) for the equivalent dose of anthracycline, while PFR of the LV dropped from 2.82 +/- 0.76 (EDV/s) to 2.41 +/- 0.55 after doxorubicin (p = 0.004). No difference was found between 1 and 12 months after the end of the treatment in 25 patients in Group 1 and 28 patients in Group 2. These results confirm the advantage of EPI over DXR in terms of cardiotoxicity and help explain the relationship of cellular damage mechanisms with the functional parameters of nuclear investigation.

CONCLUSION

A possible explanation for specific alteration after DXR could be the increased production of semiquinone free radicals, which are known to induce membrane damage and, consequently, myocardial edema and diastolic alteration.

Almotriptan and Its Combination with Aceclofenac For Migraine Attacks: A Study of Efficacy and The Influence of Auto-Evaluated Brush Allodynia

Early treatment and combining a triptan with a non-steroidal anti-inflammatory drug (NSAID) are thought to improve outcome during migraine attacks, possibly by counteracting the negative influence of cutaneous allodynia. The aim of this multicentre, double-blind pilot study was to evaluate the prevalence of brush allodynia and its relative influence on the efficacy of a triptan-NSAID combination compared with headache intensity at the time of treatment. In a randomized, cross-over design, 112 migraineurs treated two moderate or severe attacks with almotriptan 12.5 mg combined with either aceclofenac 100 mg or placebo. Patients used a 2-cm brush to assess cutaneous allodynia. Allodynia was reported in 34.4± of attacks. The almotriptan-aceclofenac combination was numerically superior to triptan-placebo on 2-24-h sustained pain-free ( P = 0.07), 2-h pain-free ( P = 0.07) and headache recurrence ( P = 0.05) rates, but not on 1-h headache relief. Allodynia numerically reduced treatment success overall, but this effect was not significant for the primary outcome measures. Headache intensity had a significant negative influence on 1-h relief in both attacks ( P = 0.0001 and 0.0008, X2) and on 2-24-h sustained pain-free rates in triptanplacebo-treated attacks ( P = 0.013). Multivariate logistic regression analysis confirmed that headache intensity at treatment intake, rather than allodynia, significantly influenced most outcome measures, predominantly so in attacks treated with almotriptan and aceclofenac. In the latter, severe compared with moderate headache intensity reduced the likelihood of achieving the primary efficacy end-points [odds ratios (OR) 0.12 and 0.33], whereas allodynia was not a significant explanatory variable (OR 0.76 and 0.65). The results apply to the protocol used here and need to be confirmed in larger studies using quantitative sensory testing.

Understanding the effects of diet on bacterial metabolism in the large intestine

Recent analyses of ribosomal RNA sequence diversity have demonstrated the extent of bacterial diversity in the human colon, and have provided new tools for monitoring changes in the composition of the gut microbial community. There is now an excellent opportunity to correlate ecological niches and metabolic activities with particular phylogenetic groups among the microbiota of the human gut. Bacteria that associate closely with particulate material and surfaces in the gut include specialized primary degraders of insoluble substrates, including resistant starch, plant structural polysaccharides and mucin. Butyrate-producing bacteria found in human faeces belong mainly to the clostridial clusters IV and XIVa. In vitro and in vivo evidence indicates that a group related to Roseburia and Eubacterium rectale plays a major role in mediating the butyrogenic effect of fermentable dietary carbohydrates. Additional cluster XIVa species can convert lactate to butyrate, while some members of the clostridial cluster IX convert lactate to propionate. The metabolic outputs of the gut microbial community depend not only on available substrate, but also on the gut environment, with pH playing a major role. Better understanding of the colonic microbial ecosystem will help to explain and predict the effects of dietary additives, including nondigestible carbohydrates, probiotics and prebiotics.

Cultivable bacterial diversity from the human colon

Knowledge of the composition of the colonic microbiota is important for our understanding of how the balance of these microbes is influenced by diet and the environment, and which bacterial groups are important in maintaining gut health or promoting disease. Molecular methodologies have advanced our understanding of the composition and diversity of the colonic microbiota. Importantly, however, it is the continued isolation of bacterial representatives of key groups that offers the best opportunity to conduct detailed metabolic and functional studies. This also permits bacterial genome sequencing which will accelerate the linkage to functionality. Obtaining new human colonic bacterial isolates can be challenging, because most of these are strict anaerobes and many have rather exact nutritional and physical requirements. Despite this many new species are being isolated and described that occupy distinct niches in the colonic microbial community. This review focuses on these under-studied yet important gut anaerobes.

[Significance of permanent atrial fibrillation in idiopathic dilated cardiomyopathy]

The significance of atrial fibrillation (AF) in idiopathic dilated cardiomyopathy (IDCM) remains discussed. The purpose of the study was to evaluate the clinical significance of permanent atrial fibrillation in patients with IDCM.

METHODS

Systematic noninvasive and invasive studies including Holter monitoring, measurement of left ventricular ejection fraction (LVEF), electrophysiological study and coronary angiography were performed in 323 patients with IDCM; all patients had a left ventricular ejection fraction (LVEF)<40%. The studies were indicated for spontaneous ventricular tachycardia (VT) in 69 patients, syncope in 103 patients and nonsustained VT on Holter monitoring in 151 asymptomatic patients. Sixty-five patients were in permanent AF (group I). Remaining patients were in sinus rhythm at the time of evaluation (group II). Programmed ventricular stimulation using up to 3 extrastimuli in control state and if necessary after isoproterenol was systematic. Patients were followed 3+/-2 years.

RESULTS

Mean age was significantly older in group I (61+/-8 years) than in group II (52+/-12) (P<0.01). Syncope (31 vs 36%), spontaneous sustained VT (18 vs 23%); mean LVEF (28+/-9% vs 29+/-9%), VT induction (25 vs 35%) were similar in both groups. During the follow-up, there were no statistical differences between groups I and II concerning each event: sudden death occurred in 13 patients, 1.5% of group I patients and 5% of group II patients (NS); a death related to heart failure occurred 22 patients, 5% of group I patients and 7% of group II patients (NS); heart transplantation was performed in 13 patients, 8% of group I patients and 3% of group II patients (NS).

CONCLUSIONS

An older age is the only significant clinical factor associated with the presence of a permanent atrial fibrillation in idiopathic dilated cardiomyopathy. The presence of permanent AF does not increase the induction of a sustained ventricular tachycardia and does not affect the general prognosis of IDCM.

Supraventricular tachyarrhythmia as a cause of sudden cardiac arrest

INTRODUCTION

Supraventricular tachyarrhythmias (SVTA) are an accepted cause of cardiac arrest in patients with Wolff-Parkinson-White syndrome (WPW) and hypertrophic cardiomyopathy but their participation in other conditions is less well understood. The purpose of the study was to examine the role of SVTA in sudden cardiac arrest (SCA) by comprehensive evaluation of patients successfully resuscitated from SCA.

METHODS

A total of 169 survivors of SCA in the absence of acute myocardial infarction underwent systematic evaluation that included echocardiography, Holter monitoring, coronary angiography and electrophysiological study (EPS) with additional testing in selected cases using provocative drug testing with isoproterenol, ajmaline or ergonovine.

RESULTS

SVTA was found as the only possible cause or as the cause facilitating SCA in 29 patients: (1) 3 had a WPW syndrome related to accessory pathway with short refractory period; (2) for 12 patients, SVTA was the cause of cardiovascular collapse; heart disease (HD) was present in 11 cases, but disappeared in two of four with dilated cardiomyopathy after the restoration of sinus rhythm; (3) in 14 patients, SVTA degenerated either in a VF or ventricular tachycardia (VT); HD was present in 12 cases, but disappeared in one; two had no HD and recurrent similar arrhythmia was documented by cardiac defibrillator in one of them. SVTA induced coronary ischemia was the main cause of SCA.

CONCLUSION

Rapid SVTA was a cause of SCA, either by cardiovascular collapse or by the degeneration in VT or VF. The complication generally occurred in patients with advanced HD or with rapid SVTA-induced cardiomyopathy and rarely in patients without HD. The incidence of SVTA as the only cause or the facilitating cause of SCAs is probably underestimated, because it is difficult to prove.

[Significance of isuprel infusion in unexplained syncope after myocardial infarction]

The prognosis for patients with complications and syncope following myocardial infarction depends on the left ventricular ejection fraction (LVEF) and the mechanism of the syncope. The aim of this study was to evaluate the results of an electrophysiological study (EPS) following isoproterenol infusion in patients with a negative EPS under basal conditions. The population included 60 patients, aged 60 +/- 12 years, 5 of whom had syncope on effort or with stress. The EPS included measurement of AV conduction, with programmed atrial and ventricular stimulation. It was repeated following infusion of 2 to 4 microg/kg of isoproterenol.

RESULTS

An arrhythmia was identified as preceding the syncope in 27 patients (45%): ventricular tachycardia (VT) n = 16, supraventricular tachycardia (n = 5), 2nd or 3rd degree AV block (n = 3), vaso-vagal reaction (n = 3): 3 subjects developed coronary ischaemia. The subjects with VT on Isuprel differed from those without VT, with a lower LVEF (34 +/- 8 vs 45 +/- 14%) (p < 0.05), a higher incidence of effort related syncope (4 vs 1) and a higher risk of cardiac death (6/16 vs 2/44) (p < 0.01). In conclusion, we recommend repeating the electrophysiogical test under Isuprel in patients with complications after MI and a negative EPS in the basal state whether or not they have exercise related syncope, which will reveal an arrhythmia in 45% of cases. Subjects with inducible VT are at high risk of cardiac death.

[Prevalence of supraventricular tachycardia and tachyarrhythmias in resuscitated cardiac arrest]

Supraventricular arrhythmias are considered to be benign when the ventricular rate is slowed and treated by anticoagulants. The aim of this study was to determine the possible influence of these arrhythmias in resuscitated cardiac arrest. Between 1980 and 2002, 151 patients were admitted after a cardiac arrest. Supraventricular arrhythrmias were identified as a possible cause of the cardiac arrest in 21 patients. They underwent echocardiography, exercise stress test, Holter ECG monitoring , coronary angiography and electrophysiological investigation. After these investigations, three patients had a malignant form of the Wolff-Parkinson-White syndrome, two were asymptomatic and, in the third patient, ventricular fibrillation was induced by treatment with diltiazem. In 8 patients, a rapid supraventricular arrhythmia was considered to be the cause of cardiac arrest by cardiogenic shock; 2 patients had hypertrophic cardiomyopathy, 5 had severe dilated cardiomyopathy which regressed in one patient. In ten patients, cardiac arrest due to ventricular tachycardia or fibrillation was provoked by a rapid (> 220 beats/min) supraventricular arrhythmia; two patients had no apparent underlying cardiac pathology. In the others, myocardial ischaemia or acute cardiac failure were considered to be the cause of the cardiac arrest. The authors conclude that rapid supraventricular arrhythmias may cause cardiac arrest either by cardiogenic shock or degenerescence to ventricular tachycardia or fibrillation. Usually, this event occurs in patients with severe cardiac disease but it may occur in subjects without cardiac disease or by an arrhythmia-induced cardiomyopathy.

Hypoxaemia associated with an enlarged aortic root: a new syndrome?

OBJECTIVE

To assess the mechanisms through which an enlarged aortic root may facilitate right to left shunting through a patent foramen ovale.

PATIENTS

19 patients with the platypnoea-orthodeoxia syndrome (POS) were compared with 30 control patients without platypnoea.

INTERVENTIONS

Multiplane transoesophageal echocardiography.

MAIN OUTCOME MEASURES

The aortic root diameter, atrial septal dimension behind the aortic root, and amplitude of the phasic oscillation of the septum were measured. Four groups of patients were compared: 12 platypnoeic patients with a dilated aortic root (POS-D), 7 platypnoeic patients with a normal aortic root (POS-N), 15 control patients with a dilated aortic root (CONT-D), and 15 control patients with a normal aortic root (CONT-N).

RESULTS

In POS-D and CONT-D patients, the apparent atrial septal dimension was 16.3 (2.7) mm and 17.4 (5.9) mm respectively, compared with 24.4 (5.2) mm in POS-N patients and 25 (4) mm in CONT-N (p < 0.005). Furthermore, the amplitude of septal oscillation was 14.7 (2.5) mm in the POS-D group versus 5.8 (2.4) mm in CONT-N (p < 0.001) compared with 23.3 (3) mm in seven patients with an atrial septal aneurysm (p < 0.001).

CONCLUSION

Patients with an enlarged aorta have an apparently smaller dimension and increased mobility of the atrial septum. These findings appear to result from compression by the aortic root and decreased septal tautness. Consequently, a "spinnaker effect" with the inferior vena caval flow may take place, opening the foramen ovale and leading to sustained right to left shunting.

[Causes and prognosis of syncope in patients with primary dilated cardiomyopathy]

The causes of adverse prognosis of patients with primary dilated cardiomyopathy remain controversial. Classically, it is thought that syncope is associated with an increased risk of mortality. The aim of this study was to try and identify the causes and prognostic significance of syncope in patients with primary dilated cardiomyopathy. Sixty-five patients aged 31 to 80 with primary dilated cardiomyopathy were admitted for investigation of syncope. The average ejection fraction was 27 +/- 10%. Invasive and non-invasive investigations including complete electrophysiological investigations, were performed. Sustained monomorphic ventricular tachycardia was induced in 14 patients (21.5%), ventricular flutter or fibrillation was induced in 9 patients (14%), a supraventricular arrhythmia in 17 patients (26%), and a conduction defect alone or associated with another arrhythmia in 7 patients (11%). A pathological result of tilt testing was observed in 5 patients (8%). No cause of syncope could be demonstrated in 15 patients (23%). During follow-up (4 +/- 2 years) there was a mortality of 15% which was only correlated with the reduction in left ventricular ejection fraction. The authors conclude that there are many causes of syncope in primary dilated cardiomyopathy: ventricular arrhythmias represent only 35% of cases and do not impact on the prognosis; above all, left ventricular ejection fraction is the most important prognostic factor.

[Does syncope change the results of programmed ventricular stimulation in patients with previous myocardial infarction?]

The induction of a ventricular tachycardia (VT) after myocardial infarction (MI) is associated with a high risk of VT and sudden death (SD) in asymptomatic patients; the purpose of the study was to know if syncope modifies the results of programmed ventricular stimulation (PVS) and the clinical consequences.

METHODS

PVS using two and three extra stimuli delivered in two sites of right ventricle was performed in 1057 patients without spontaneous VT or resuscitated SD at least 1 month after an acute MI; 836 patients (group I) were asymptomatic and were studied for a low ejection fraction or nonsustained VT on Holter monitoring or late potentials; 228 patients (group II) were studied for unexplained syncope. The patients were followed up to 5 years of heart transplantation.

RESULTS

Sustained monomorphic VT (< 280 b/min) was induced in 238 group I patients (28%) and 62 group II patients (29%); ventricular flutter (VT > 270 b/min) or ventricular fibrillation (VF) was induced in 245 group I patients (29%) and 42 group II patients (18%) (P < 0.05); PVS was negative in 353 group I patients (42%) and 124 (55%) group II patients (NS). The patients differ by their prognosis; cardiac mortality was 13% in group I patients and 34% in group II patients with inducible VT < 280 b/min (P < 0.01), 4% in group I patients and 13% in group II patients with inducible VF (P < 0.05), 5% in group I patients and 7% in group II patients with negative study (NS). In conclusion, syncope did not change the results of programmed ventricular stimulation after myocardial infarction. However, syncope increased significantly cardiac mortality of patients with inducible ventricular tachycardia, flutter or fibrillation.

[Non-revascularisation of acute coronary syndrome with ST elevation]

National therapeutic strategies in acute coronary syndromes (ACS) required revaluation, especially with regards to reperfusion. RICO is an observatory of ACS in the Côte d'Or district. Between January 1st 2001 and April 31st 2003, the cases of 706 patients with ACS and persistent ST elevation or appearances of left bundle branch block eligible for revascularisation (admitted < 12 hours after onset of symptoms and no contra-indications to thrombolysis), were reviewed. The number of revascularised patients was 488 (69%) and 218 (31%) were not revascularised. Thrombolysis was the most commonly used method of revascularisation (66%) in this district: 34% underwent primary angioplasty. Multivariate analysis showed only three independent predictive factors of non-reperfusion during the acute phase. They were: age (> or = 75 years) (p < 0.001), left bundle branch block (p = 0.002) and hospital admission > or = 6 hours after onset of symptoms (p < 0.001). These results confirm the utility of developing networks to improve the efficacy of management and reduce the delay before hospital admission. They also identify specific population groups, the elderly for example, who require specific therapeutic strategies for coronary revascularisation in ACS.

[Risk factors for cardiac mortality in cases of syncope with previous history of myocardial infarction]

Syncope is considered to be a clinical sign predictive of sudden death in patients with a previous history of myocardial infarction. The aim of this study was to determine the prognostic factors in this population. The study population included 228 patients with myocardial infarction over one month old and who had no documented ventricular tachycardia. The patients were referred for investigation of syncope. The left ventricular ejection fraction (LVEF) was measured by echocardiography or radionucleide technique. Complete electrophysiological study including programmed atrial and ventricular stimulation was performed in all cases. The patients were followed up for 6 months to 5 years or until cardiac transplantation (average 3+/-1 years). One hundred and nineteen patients had a LVEF <40% (Group I) and 109 patients had a LVEF >40% (Group II). Sustained monomorphic ventricular tachycardia (VT) with a rate inferior to 280/min was induced in 44 patients in Group I (37%) and in 18 patients in Group II (16.5%), p<0.05. Ventricular flutter or fibrillation was induced in 24 patients in Group I (19%) and in 19 patients in Group II (17%) (NS). Different causes of syncope (conduction disturbances, supraventricular tachycardia, increased vagal tone, severe coronary ischaemia) were found in 23 patients in Group I (19%) and 32 patients in Group II (29%) (NS). Syncope was unexplained in 43 patients in Group I (36%) and 40 patients in Group II (37%) (NS). The prognosis was very different. In Group I, the cardiac mortality was 49% in patients with inducible monomorphic VT <280/min, 35% in those with inducible ventricular flutter or fibrillation but only 9% in patients without inducible ventricular arrhythmias. In Group II, the prognosis was independent of the results of programmed stimulation and much better: cardiac mortality was 5.5% in patients with inducible VT, 5% in those with inducible ventricular flutter or fibrillation and 4% in patients without inducible ventricular arrhyhtmias. The authors conclude that LVEF is the most powerful predictor of cardiac mortality and sudden death in cases of syncope with a past history of myocardial infarction. The prognosis also depends on the results of programmed ventricular stimulation when the LVEF is inferior to 40%. Sustained monomorphic VT is the most frequently induced arrhythmia in this case and the prognosis of these patients is particularly poor. On the other hand, syncope does not appear to be a poor prognostic factor in the group with normal LVEF, even when it is possible to induce VT.

[Anti-digoxin antibodies in severe digitalis poisoning in an 11-day old infant. Review of the literature]

Acute digitalis intoxication bringing into play the prognosis for survival is a rare complication in children, particularly in the neonatal period. We describe the case of an accidental massive digitalis intoxication in a newborn aged 11 days, which caused a complete atrioventricular block and a state of cardiogenic shock. The outcome was favorable four hours after administration of the first dose of anti-digoxin antibodies, with a complete reversal of clinical and electrocardiographic signs. The onset of first-degree atrioventicular block 48 hours afterward made us consider the possibility of the tissular salting-out effect of the digoxin and led us to administer a second dose of specific antibodies. The originality of this case has to do with the severity of the initial clinical picture, its total reversal with antibodies and the salting-out phenomena that followed. The case reminds us, along with the data in the literature, the criteria of wrong prognoses in massive digitalis intoxication in the child and the indications for anti-digoxin antibodies.

Predictors of atrial flutter with 1:1 conduction in patients treated with class I antiarrhythmic drugs for atrial tachyarrhythmias

OBJECTIVES

The purpose of the study was to look for the predictor factors of atrial proarrhythmic effects of class I antiarrhythmic drugs.

BACKGROUND

Class I antiarrhythmic drugs may induce or exacerbate cardiac arrhythmias. The predictors of ventricular proarrhythmia are known. The predictors of atrial flutter with 1:1 conduction are unknown.

METHODS

Clinical history, EGG, signal-averaged EGG (SAECG) and electrophysiologic study were analysed in 24 cases of 1:1 atrial flutter with class I AA drugs and in 100 control patients without history of 1:1 atrial flutter with class I AA drugs.

RESULTS

The ages of patients varied from 46 to 78 years. Underlying heart disease was present in nine patients. The surface EGG revealed the presence of a short PR interval (PR<0.13 ms), visible in leads V5, V6 in eight (35%) patients with normal P wave duration; in other patients with prolonged P wave duration, PR seemed normaL On SAECG recording, there was a pseudofusion between P wave and QRS complex. The electrophysiologic study revealed some signs indicating a rapid AV nodal conduction (short AH interval or rate of 2nd degree AV block at atrial pacing >200 beats/mm) in 19 of the 23 studied patients. All patients, except one, had at least one sign indicating a rapid AV nodal conduction (short PR and/or P wave-QRS complex continuity on SAECG). In the control group, seven patients (7%) had a short PR interval (P<0.01) and 11 (11%) had a pseudofusion between P wave and QRS complex on SAECG (P<0.001). The P wave-QRS complex pseudofusion on SAECG had a sensitivity of 100% and a specificity of 89% for the prediction of an atrial proarrhythmic effect with class I antiarrhythmic drug.

CONCLUSION

We recommend avoiding class I AA drugs in patients with a short PR interval on surface EGG and to record SAECG in those with apparently normal PR interval to detect a continuity between P wave and QRS complex, which could indicate a rapid AV nodal conduction, predisposing to 1:1 atrial flutter with the drug.

Long-term prognostic value of 201Tl single-photon emission computed tomographic myocardial perfusion imaging after coronary stenting

BACKGROUND

The prognostic value of (201)Tl myocardial imaging has been demonstrated in several studies concerning patients with a known significant coronary artery disease. However, the evolution of a coronary stenosis after stenting is difficult to predict. This study was designed to assess the prognostic value of (201)Tl single-photon emission computed tomography (thallium SPECT) perfusion imaging in patients after intracoronary stenting.

METHODS

One hundred fifty-two patients were studied. They were followed up during 40 +/- 13 (mean +/- SD) months after thallium SPECT. Stent-related events were studied after thallium stress testing and included cardiovascular death, myocardial infarction, and revascularization. Stress thallium imaging was performed 5 +/- 2 months after stenting, and ischemia was considered to be present if at least 2 contiguous segments were showing reversible defects.

RESULTS

Only 3 (3%) among the 105 nonischemic patients had major cardiac events during the follow-up versus 13 (28%) of the 47 ischemic patients (P < .001) after thallium SPECT. The relative risk of major cardiac events for patients with significant ischemia was 10.5 compared with nonischemic patients (P < .001). Fourteen (30%) of the ischemic patients and 8 (8%) among the nonischemic patients underwent iterative revascularization (P < .001). Therefore, only 11 (10%) of the nonischemic patients had major cardiac events or revascularization compared with 24 (51%) of the ischemic patients (P < .001).

CONCLUSIONS

Absence of ischemia on thallium SPECT imaging at 5 months after coronary stenting indicates a low risk for cardiovascular events or interventional procedure. These results may have important clinical implications in patient treatment.

[Medico-economic impact of the Program of Medicalization of the Information System on hospital stay for myocardial infarction: influence of the quality of data collection and hospitalization length]

The aim of the Medicalisation Program of the Information System was to describe the activity of hospital for budget allocation. This work concerned the whole hospitalizations in the unit of intensive care of cardiology of Dijon for a myocardial infarction (MI) during the 1st half of 1998 (59 patients). The objectives of this study were: 1) the estimate of the real cost of MI management; 2) the comparison of this cost with the reference cost, determined from the data of the National Basis of Costs (BNC); 3) the economic impact of the quality of coding. The real global cost of MI was estimated at 2,323,542 FF (average by patient: 39,382 +/- 15,718 FF). Sixty eight per cent of the costs are directly related to the standing fixed overheads; in contrast, the medical and the therapeutic acts accounted for only 32% of the estimated real cost. A 52% over-estimation was highlighted between the estimated real cost and the cost of reference (p < 0.001). The errors of coding accounted for an under-estimation of only 3.6% of the cost of reference. The duration of hospitalization was significantly higher than the stay length taken from the national reference database (12.9 +/- 5.4 versus 9.2 +/- 2.1 days; p < 0.001), and was mainly responsible for these discrepancies of costs.

[Magnetic resonance imaging of dilatation of the ascending aorta after repair of coarctation of the aorta]

The authors studied the risk factors for dilatation of the ascending aorta in patients operated for coarctation of the aorta. A prospective study of the diameters of the ascending aorta by magnetic resonance imaging was undertaken in 46 patients with an average age of 30 months (range 6 days to 11 years) at surgery, and 10 years of age (6 months to 31 years) at the time of the investigation. The diameters were measured at the level of the sinus of Valsalva, at the sino-tubular junction, and compared with reference tables with respect to body surface area. Twenty six per cent of patients had dilatation of the ascending aorta. The predisposing factors were investigated. Age, type of surgery, postoperative hypertension. Doppler gradient in the isthmic region, anatomical appearances of the repair observed by MRI were not predictive of this complication. On the other hand, age of patients at MRI and bicuspid aortic valves (present in 66% of cases) (p < 0.05) were significant risk factors. These results indicate that regular follow-up by echocardiography or MRI of the diameter of the ascending aorta is necessary in patients operated for coarctation of the aorta and with bicuspid aortic valves.

Treatment of migraine attacks with intranasal alniditan: an open study

In this open phase-II clinical tolerability trial 17 neurologists enrolled a total of 112 patients and instructed them to administer a maximum of two doses of intranasal alniditan, a 5-HT1B/D receptor agonist, for the treatment of three consecutive migraine attacks of moderate to severe intensity. A second dose of the trial medication was allowed within 1-24 h after the first administration. At 1 h after intranasal administration, 70/103 (68%) patients had responded to treatment (reduction from severe or moderate headache before treatment to mild or no headache) after their first migraine attack, 65/94 (69%) after their second and 52/75 (71%) after their third. In 187/270 (69%) of all attacks, patients were considered responders at 1 h. The median time to onset of effect was 30 min. The migraine headache recurred in 44% (attack 1), 55% (attack 2) and 44% (attack 3) after 4-5 h. Sixty-eight per cent of the patients reported nasal irritation, 19% taste disturbance and 44% throat irritation. Alniditan 2 mg, administered via the intranasal route, was effective in relieving migraine headaches in over two-thirds of the patients at 1 h.

[Paroxysmal junctional tachycardia and normal ECG in sinus rhythm. Is their mechanism influenced by the age of the patient at the time of the study?]

At the time of the curative treatment of paroxysmal junctional tachycardias, to determine the mechanism of the tachycardia is important. Five-hundred forty intracardiac or esophageal electrophysiological studies were performed in patients aged from 9 to 86 years and then revieved. There was no preexcitation syndrome on surface ECG. Programmed atrial stimulation was performed in basal state and if necessary repeated after infusion of isoproterenol. Atrioventricular nodal reentrant tachycardia was the most frequent cause of junctional tachycardia (72%) since childhood and in all stages of life. Concealed accessory pathway reentrant tachycardias were identified in 22% of tachycardias with a stable incidence during the course of life. Various mechanisms of tachycardia were identified in the remaining patients. In conclusion, the mechanism of paroxysmal junctional tachycardia is not correlated with the age of the patient.

[Specific factors of diabetes in the rehabilitation of coronary patients]

This prospective controlled trial included two groups of subjects with coronary artery disease: one of 33 patients with non-insulin-dependent diabetes mellitus (6 females and 27 males, mean age 57 +/- 9 years, left ventricular ejection fraction of 56 +/- 14%) and the control group of 33 subjects without diabetes (3 females and 33 males, mean age of 57 +/- 11 years, LVEF of 58 +/- 11%). Before training heart rate was faster for patients with diabetes at rest (72 +/- 11 vs 66 +/- 81 bpm, p = 0.03) and at the end of the stress test (127 +/- 15 versus 118 +/- 18 bpm, p = 0.03). After rehabilitation, resting heart rate and peak heart rate were similar. However cardiovascular capacities improvement was better in subjects without diabetes mellitus, especially concerning peak VO2 (28.98 +/- 8.88 versus 22.78 +/- 6.28 mL/min/kg, p < 0.01) and mechanical power (138 +/- 48 versus 118 +/- 23 watts, p < 0.01). Two groups were retrospectively distinguished among diabetic patients: one group of 17 patients showing a VO2 improvement superior to 5% and a second group non improved (VO2 < 5%). For the second group the two selective factors were higher fasting glycemia (1.83 +/- 0.75 versus 1.31 +/- 0.38 g/L, p = 0.01) and higher hemoglobin A1C (8.05 +/- 2.04 vs 6.62 +/- 1.03%, p = 0.02). Heart rate variability was not significantly different for these two groups: changes in autonomic nervous system cannot explain resistance of diabetic subjects to training. On the other hand, principal aim must be the equilibrium of glycemia in the management of diabetes.

[Action of sotalol on high-amplification electrocardiogram]

D,l sotalol is an antiarrhythmic widely used for treating ventricular excitability, especially ventricular tachycardia (VT). The means of assessing its efficacy is 24 hour Holter monitoring and programmed ventricular stimulation. High amplification ECG has also been proposed for predicting the effects of the drug on the induction of VT. The aim of this study was to assess the results of high amplification ECG before and after taking sotalol and to compare them with those of programmed ventricular stimulation. This study was performed in 24 patients with spontaneous and inductible ventricular tachycardia due to ischaemic heart disease. The two investigations were performed under basal conditions and after treatment with 160 to 320 mg/day of d,l-sotalol for 8 days. Nine patients had VT which could not be induced after treatment. In the other 15 cases, the VT remained inducible and was not significantly slowed. Analysis of different parameters of high amplification ECG, the QRS duration, RMS 40 and LAS did not show any difference after treatment in cases with inducible VT or VT suppressed by treatment. In conclusion, d,l sotalol, even at antiarrhythmic doses, does not seem to change the parameters of high amplification ECG, and it is therefore not necessary to stop treatment to carry out this investigation. Moreover, it was impossible to predict the effect of d,l sotalol on VT by high amplification ECG.

Reproducibility of response to programmed atrial stimulation

The induction of atrial tachyarrhythmias (ATAs) is used to guide the medical or ablative treatment of these tachycardias. To date no information is available regarding the reproducibility of programmed atrial stimulation (PAS) induced ATA. The purpose of the study was to look for the reproducibility of PAS. Two baseline electrophysiological tests were performed in the drug-free state and within 6 months to 3 years of one another (mean 18 months) in 62 patients. Twenty-six patients had spontaneous documented ATAs (group I); 36 patients did not have spontaneous ATAs (group II). PAS used one and two extrastimuli delivered during three cycle lengths (sinus rhythm, 600 ms, 400 ms). The results were as follows. In group I, sustained (> 1 minute) ATA was induced in 23 patients on the first PAS and remained inducible in 22 patients in the second study. In three patients with noninducible ATA, PAS remained negative in only one; the reproducibility of PAS was 88%. In 17 (47%) group II patients, a sustained ATA was induced in the first study, and the ATA remained inducible in 10 patients in the second study. Nineteen other patients did not have inducible ATA on the first study, but 10 of them had an inducible ATA on the second PAS; the reproducibility of PAS was 53%. In conclusion, long-term reproducibility of PAS induced ATA in patients with spontaneous and documented ATA was good. In patients without spontaneous ATA, the reproducibility of PAS induced ATA was low and the induction of ATA in these patients should be interpreted cautiously in light of this observed variability in induced atrial arrhythmias.

Long-term reproducibility of ventricular tachycardia induction with electrophysiological testing in patients with coronary heart disease and depressed left ventricular ejection fraction

The Multicenter Automatic Defibrillator Implantation Trial (MADIT) has recently confirmed the role of programmed ventricular stimulation (PVS) to identify the high risk patients of sudden death after myocardial infarction and to prevent this risk. The purpose of this study was to evaluate the long-term reproducibility of PVS in these patients. Thirty patients with coronary heart disease without spontaneous documented sustained ventricular tachycardia (VT) underwent two programmed stimulations in the absence of antiarrhythmic drug treatment between 2 and 6 years (mean 4 years). No patient had a myocardial infarction or intervening cardiac surgery during this period. The protocol of study was similar using up to three extrastimuli in two sites of the right ventricle, delivered in sinus rhythm and driven rhythm (600 ms, 400 ms, respectively). On the first PVS, 17 patients had inducible sustained VT (group I). Thirteen patients did not have inducible VT (group II). On the second PVS all group I patients but one had inducible VT, but the cycle length was significantly modified in 11. In group II, five patients had inducible VT and in the other patients the PVS remained negative. In conclusion, in patients with coronary heart disease, but without documented VT, the long-term reproducibility of PVS was excellent in those with inducible VT (94%); the patients remain at risk of VT and a prophylactic implantable cardioverter defibrillator could be considered. In patients with initially negative study, reproducibility of PVS was lower (61.5%), probably because of the progressive remodeling after myocardial infarction. Therefore, the occurrence of new symptoms in patients with previously negative study requires a second programmed ventricular stimulation.

[Predictive value of induction of atrial flutter or fibrillation in paroxysmal junctional tachycardia]

The association of different types of tachycardia in a given patient is a well-known phenomenon and the development of ablative methods rises hopes that treatment of one of them may suppress the others. The aim of this study was to determine the significance of induction of atrial flutter or fibrillation (AF) during electrophysiological investigation of patients investigated for paroxysmal junctional tachycardia. The initial population of 500 patients was limited to 485 patients, aged 12 to 86, with a normal intercritical ECG and without a Wolff-Parkinson-White syndrome, who underwent electrophysiological investigation for junctional tachycardias since 1978 and in whom the tachycardia could be reproduced. The study was performed by the endocavitary approach in 262 cases and by the transoesophageal approach in 213 cases with a similar protocol, programmed atrial stimulation with 1 and 2 extrastimuli under basal conditions, eventually completed by the repetition of the protocol with low doses of isoproterenol. The electrophysiological study showed that the tachycardia involved a latent bundle of Kent in 103 cases, a double nodal pathway in 343 cases or another circuit in 39 cases. During this study, sustained AF was induced in 66 cases (13.5%) with a similar incidence in Kent bundles (14.5%), intranodal reentry (11%) and other forms of reentry (11%). During follow-up, ranging from 6 months to 10 years, 7 patients with induced AF and 9 without inducible tachycardia, developed permanent AF. The occurrence of the arrhythmia was significantly correlated with the mechanism of reentry (latent Kent 8/103 cases, intranodal reentry 8/343 cases, p < 0.05), and with the induction of the same arrhythmia by oesophageal investigation alone (p < 0.001). The initiation of the arrhythmia by endocavitary stimulation did not seem to have any positive predictive value. In conclusion, the induction of atrial flutter or fibrillation during investigation of a subject with paroxysmal junctional tachycardia without a patent Wolff-Parkinson-White syndrome, does not seem to be predictive of future development of atrial flutter or fibrillation, unless the investigation was undertaken by the oesophageal approach.

[Randomized comparison of 4F and 6F catheters for diagnostic coronary angiographies via the femoral approach]

The use of 6F catheters has been validated for coronary angiography. The use of small-caliber catheters is a more recent development. The aim of this study was to assess the feasibility, the cost and complications of coronary angiography using the femoral approach with 4F catheters. The authors undertook a randomized prospective study of 4F Care Infiniti catheters (N = 100) and 6F Spertorque Plus catheters (N = 100) in hospitalised patients. Criteria of non-inclusion were valvular pathology, acute myocardial infarction, aorto-coronary bypass or aorto-femoral bypass procedures. No statistical difference was observed between the two groups with respect to feasibility, to duration of the procedure, or of irradiation or to cost. The quality of the angiograms was good except in one patient in the 4F group; 4 patients in the 6F group required a 4F catheter to complete their examination. Left ventricular catheterisation was more difficult with 4F catheters (p = 0.016). Use of 4F catheters was associated with injection of significantly less contrast (p = 0.00007), reduced the duration of compression (p < 10(-6)) and its complications (p = 0.004). The authors conclude that 4F catheters are safe and well tolerated. They are associated with less patient morbidity, without any loss in quality of the angiogrammes. Other studies in valvular heart disease and after coronary bypass surgery should lead to the generalisation of their use in all coronary patients.

Intrapulmonary artery and intrabronchial migration and extraction of a fragment of J-shaped atrial pacing catheter

A fragment of a fractured Telectronics Atrial Accufix 330-801 lead asymptomatically perforated the adjacent bronchus and was detected on routine chest X-ray. The metallic fragment was located by chest CT scan and bronchial fluoroscopy to lie between the right lobar bronchus and the pulmonary artery, confirming bronchial perforation. The foreign body was removed without complication by direct visualisation with rigid bronchoscopy.

MR imaging of the heart in patients after myocardial infarction: effect of increasing intersection gap on measurements of left ventricular volume, ejection fraction, and wall thickness

PURPOSE

To determine the extent to which the number of planes imaged at magnetic resonance (MR) imaging could be reduced without modifying the calculated volume and thickness of the left ventricle.

MATERIALS AND METHODS

Sixty-one patients were examined after a myocardial infarction. The whole left ventricle was imaged by using 5-mm contiguous breath-hold cine MR short-axis sections with no gap (SAng) (two-dimensional fast low-angle shot sequence, 9/4.8 [repetition time msec/echo time msec]). The effect of omitting one section in two (short-axis sections with 5-mm gap [SA5 mm]) or two sections in three (short-axis sections with 10-mm gap [SA10 mm]) was studied.

RESULTS

In the comparison of SA5 mm or SA10 mm with respect to the reference SAng, the standard error of the estimate (SEE) for the diastolic volume did not exceed the 6.1% interobserver SEE, and the SEE for the ejection fraction remained lower than the 3% interobserver SEE. The measured wall thickness was not affected. In addition, six simple geometric models were compared with SAng and yielded an SEE of 9.5%-28.1% for the diastolic volume and 3.8%-13.3% for the ejection fraction.

CONCLUSION

In the study of left ventricles with heterogeneous contractility, short-axis imaging is more accurate than geometric modeling and permits wall thickness measurements when an intersection gap of 5 or 10 mm is used.

[Long-term follow up of 115 patients with ischemic heart disease and ventricular flutter induced by programmed ventricular stimulation in the absence of ventricular arrhythmia]

The clinical significance of rapid monomorphic ventricular tachycardia (VT) (> 270 beats/min), also called ventricular flutter, remains controversial in patients without documented spontaneous sustained VT. The aim of this study was to evaluate the outcome of 115 patients with ischaemic heart disease, aged 58 +/- 10 years, without spontaneous ventricular arrhythmias, but who had inducible ventricular flutter during programmed ventricular stimulation. The patients underwent stimulation to evaluate the prognosis after myocardial infarction or to investigate a malaise with or without loss of consciousness. Sustained ventricular flutter was the only inducible arrhythmia in all patients. The mean left ventricular ejection fraction (LVEF) was 42 +/- 14%. During an average follow-up period of 66 +/- 43 months, 31 deaths, including 27 of cardiac causes, were observed. The 1, 5, and 11 year survival of the whole population was 94, 79 and 64% respectively. In univariate analysis, anterior wall myocardial infarction, a low LVEF, the presence of non-sustained ventricular tachycardia (NSVT) on 24 hour Holter monitoring and Class III antiarrhythmic treatment, were poor prognostic factors (p 0.05). In multivariate analysis, the only independent predictive factors of mortality were low LVEF (p = 0.006), the presence of NSVT on Holter monitoring (p = 0.003) and the absence of betablocker therapy (p = 0.015). Medical therapy with betablockers or the implantation of an automatic defibrillator may be indicated in these patients at higher risk.

[Ten-year experience with heart transplantation (1987-1997)]

OBJECTIVES

Analyze ten years experience with heart transplantation at the Dijon University Hospital and determine which parameters control mid and long term outcome.

PATIENTS AND METHODS

One hundred thirty six heart transplantations were performed over a 10 year period (1987-1997) in 118 men and 18 women aged 51-87 years. Heart transplantation was indicated on the basis of the following criteria: ejection fraction *20%, pulmonary arteriole resistance < 6 Wood units, peak oxygen uptake < 14 l/kg/min. The Shumway or anatomic technique was used. The triple immunosuppressive protocol combined corticosteroids, azathioprine and cyclosporin. The same team conducted the post-transplantation follow-up with regular programmed consultations in addition to those requested by the general practitioner, the cardiologist or the patient. Follow-up was oriented according to the clinical situation (blood chemistry, cell counts, cyclosporinemia, search for infection, echocardiography, endomyocardial biopsy, coronarography).

RESULTS

Five patients (3.6%) died when still on the waiting list. Absolute emergency transplantation was performed for patients (28.1%) including 8 (5.9%) after circulatory assist. Hospital mortality was 11.7% and late mortality was 16.1%. Actuarial survival was 78% at 1 year, 71% at 5 years and 69% at 10 years. Among the survivors, 94% were taking two, three or even four drugs for hypertension. Cyclosporin levels decreased and creatinine levels increased. Episodes of rejection were minimal: 86.57% of the biopsies were * grade 1 and 4.45% * grade 2. Cytomegalovirus infection was documented and treated in 7.55% of the cases. Incidence of graft coronary artery disease was 3.4% at 1 year, 6.5% at 2 years and 7.9% at 3 years.

CONCLUSION

Our follow-up structure where the same small team conducts regular examinations together with our approach to heart transplantation appears to be the main factor leading to the quality results obtained in this series.

92K-GL (MMP-9) and 72K-GL (MMP-2) are produced in vivo by human oral squamous cell carcinomas and can enhance FIB-CL (MMP-1) activity in vitro

Previous studies have shown a correlation between the production of certain matrix metalloproteinases (MMPs), especially the gelatinases, by malignant tumors and the progression of these cancers as they invade and metastasize through the extracellular matrix and basement membranes. However, very few of these studies examined this relationship in human oral cancer in vivo, and none addressed the issue of how combinations of the MMPs may further enhance tumor progression. To determine which MMPs are produced in vivo by human oral cancers, we used specific anti-human-MMP antibodies and immunocytochemistry (ICC) methods to examine oral cancer tissue specimens from 20 surgery patients. The ICC data indicated that 72-kDa (72K-GL) and 92-kDa gelatinases (92K-GL) were produced in vivo by discreet clusters of tumor cells and by stromal fibroblasts, vascular endothelial cells (72K-GL), and PMNs (92K-GL). Some stromal fibroblasts near the tumors also appeared to produce fibroblast-type collagenase (FIB-CL), a finding confirmed by Western blot analysis of media conditioned by oral tumor explant cultures. ICC results indicated that 5 of the 20 tumors coincidentally produced all three MMPs. To examine how the two gelatinases and FIB-CL may interact in vitro to degrade fibrillar type I collagen, a major structural component of the extracellular matrix, we used a modified FIB-CL activity assay. Combinations of the gelatinases and FIB-CL were incubated with a 3H-collagen substrate, with the results compared with the combination of stromelysin-1 (SL-1, a superactivator of FIB-CL) and FIB-CL. 92K-GL caused a nine-fold increase in collagenase activity, equivalent to SL-1, while 72K-GL produced a four-fold increase. These results indicate that human oral cancers produce 92K-GL, 72K-GL, and FIB-CL in vivo and that the gelatinases and FIB-CL cooperate to enhance collagen degradation greatly in vitro.

Interlaboratory study comparing the microbiological potency of spiramycins I, II and III

An interlaboratory study has been performed to determine the relative potencies of spiramycins (SPMs) I, II and III by diffusion or/and turbidimetric assays with Bacillus subtilis or Staphylococcus aureus as the test organisms. Six laboratories from three countries participated. Experimental procedures were according to the European Pharmacopoeia, 3rd ed. The activity of SPM I is markedly higher than that of SPM II and III. By diffusion, the activities of SPM II and III relative to SPM I were found to be 57 and 72%, respectively. The interlaboratory relative standard deviations (RSD) varied from 3.6 to 16.3%. By turbidimetry, the activities of SPM II and III relative to SPM I were found to be 45 and 52%, respectively. The interlaboratory RSD values varied from 2.6 to 7.7%. The results of the study were analyzed according to the ISO 5725-2 guidelines to determine the repeatability, the between-laboratory and the reproducibility variances of both methods.

Protection of Escherichia coli cells against extreme turgor by activation of MscS and MscL mechanosensitive channels: identification of genes required for MscS activity

Mechanosensitive channels are ubiquitous amongst bacterial cells and have been proposed to have major roles in the adaptation to osmotic stress, in particular in the management of transitions from high to low osmolarity environments. Electrophysiological measurements have identified multiple channels in Escherichia coli cells. One gene, mscL, encoding a large conductance channel has previously been described, but null mutants were without well-defined phenotypes. Here, we report the characterization of a new gene family required for MscS function, YggB and KefA, which has enabled a rigorous test of the role of the channels. The channel determined by KefA does not appear to have a major role in managing the transition from high to low osmolarity. In contrast, analysis of mutants of E.coli lacking YggB and MscL shows that mechanosensitive channels are designed to open at a pressure change just below that which would cause cell disruption leading to death.

Managing hypoosmotic stress: aquaporins and mechanosensitive channels in Escherichia coli

When Escherichia coli cells are subject to hypoosmotic shock they are subject to substantial flows of water that can be equivalent to a 4-5-fold increase in the pressure exerted from the cytoplasm on the membrane and peptidoglycan wall. The recently described aquaporin that facilitates rapid water movement across the cytoplasmic membrane is repressed during growth at high osmolarity. This may enable the cell to reduce the rate of pressure build up during transitions from high to low osmolarity. The presence of multiple mechanosensitive channels in the E. coli cell membrane is well documented. The recent identification of genes that inactivate the MscL and MscS channels has established their role in releasing the pressure built up by hypoosmotic shock. The isolation of specific mutations and the structural studies on MscL now pave the way to a molecular understanding of the mechanism of activation of mechanosensitive channels.

Comparison of digital rectal examination and biopsy results with the radical prostatectomy specimen

PURPOSE

Digital rectal examination is integral to staging prostate cancer. Ultrasound guided biopsy establishes the diagnosis, and it may provide useful information regarding disease grade and extent. Treatment decisions are largely based on information gained from digital rectal examination and biopsy but this information is only useful if it correlates with the radical prostatectomy specimen and prognosis. We correlated digital rectal examination and transrectal ultrasound guided biopsy results with a detailed analysis of the radical prostatectomy specimen.

MATERIALS AND METHODS

The accuracy of an abnormal digital rectal examination for predicting the location and extent of cancer was assessed in 89 patients thought to have clinical stage T2 disease. We evaluated 155 patients with clinical stages T1c and T2 disease to correlate the location of positive biopsies with the tumor site in the prostate. Radical prostatectomy specimens were completely sectioned at 2 mm. intervals, and tumor extent and location were recorded.

RESULTS

In 85 patients a unilateral lesion was suspicious on digital rectal examination, that is stage cT2. The final pathological review revealed cancer on the suspicious side in 82 cases (96%) with tumor confined to the same lobe in only 23 (27%), bilateral disease in 59 (69%) and tumor confined to the contralateral lobe in 3 (4%). In 4 patients with a palpable bilateral abnormality a bilateral lesion was confirmed on final pathological evaluation. Digital rectal examination demonstrated a 36 and 31% incidence of extracapsular tumor extension and positive surgical margins, respectively, on the clinically benign side. In 100 patients only unilateral biopsy was positive. The final pathological evaluation revealed cancer in the biopsy positive side in 95 cases (95%) with tumor confined to the ipsilateral lobe in only 26 (26%), bilateral disease in 69 (69%) and tumor confined to the contralateral lobe in 5 (5%). In 46 of the 55 patients (84%) with bilateral positive biopsies tumor involved both sides but the pathologist did not identify cancer in both lobes in 9 (16%). While 100 patients had a unilateral negative biopsy, analysis of the prostatectomy specimen revealed carcinoma in the benign lobe in 74 (74%). Moreover, extracapsular tumor extension and a positive surgical margin were observed on the biopsy negative side in 31% of the patients. The degree to which digital rectal examination and biopsy results confirmed the final pathological evaluation was assessed using the kappa statistic, which revealed only slight agreement with each factor. The correlation of digital rectal examination and biopsy results with the location of extracapsular extension and positive margins was evaluated by the Spearman coefficient of correlation, which indicated poor agreement. When patients with unilateral versus bilateral positive biopsy were compared with respect to prognostic parameters, the difference was statistically significant for initial serum prostate specific antigen, the percentage of surface involved by tumor, biopsy and final Gleason scores, and the incidence of extracapsular extension of tumor.

CONCLUSIONS

Digital rectal examination and the interpretation of prostate biopsy are not accurate clinical tools for defining the location and extent of prostatic carcinoma. Bilateral positive biopsy may be useful as an adjunct to the current clinical staging system.

Neomycin: microbiological assay or liquid chromatography?

In a multicentre study involving six laboratories, a microbiological assay was performed on three neomycin samples containing respectively, 0.12, 2.1 and 11% (m/m) of neomycin C, as well on a pure neomycin C sample. The potency was determined according to the European Pharmacopoeia method but using a neomycin B base standard. The relative standard deviations between laboratories (RSD) on the potencies varied from 4.8 to 50%, depending on the sample examined. The RSD increased with the neomycin C content of the samples and the highest RSD values were observed for the pure neomycin C sample. The activity of neomycin C relative to neomycin B was found to be 62% by diffusion (RSD:41%) and 56% by turbidimetry (RSD: 50%). This confirmed that the presence of neomycin C in a neomycin sample influences the reproducibility of the microbiological assay. T estimate the influence of this effect on official standard, their composition was verified by liquid chromatography. The neomycin C base content of the standards varied between 0.4 and 5.8% (m/m). Based on the results obtained and on formerly published reports discussing problems encountered with microbiological assay of neomycin, it is proposed to introduce liquid chromatography in official monographs to replace microbiological assay.

[Comparison of gas exchange and hemodynamic variables during 2 types of exercise tests. Cycle-ergometry and the ergometric table]

The development of stress echocardiography on an ergometric table has increased the number of stress tests in the decubitus position, whereas most of the information currently available concerns stress tests in the sitting position or on the treadmill. In order to study the influence of this position of stress testing, the authors compared the results obtained in a series of 15 patients without cardiac disease (Group I) and another series of 15 coronary patients (Group II) undergoing the two types of stress testing, in the vertical position on a bicycle ergometer and in the lateral decubitus position on the ergometric table. Effort tolerance on the bicycle ergometer was significantly greater in terms of work load (202 +/- 35 vs 180 +/- 36 watts (p < 0.001) in the controls, and 120 +/- 32 vs 106 +/- 22 watts (p < 0.05) in the coronary group), of duration of effort (19 +/- 3 vs 16 +/- 3 minutes (p < 0.001) in the controls and 10 +/- 3 vs 8 +/- 2 minutes (p < 0.05) in the coronary patients), of heart rate (190 +/- 10 vs 172 +/- 21 beats/min (p < 0.005) in controls and 118 +/- 19 vs 111 +/- 14 beats/min (p < 0.05) in the coronary patients). On the other hand, blood pressure and O2 saturation tended to be greater during exercise in the decubitus position: SBP 200 +/- 23 vs 196 +/- 27 mmHg (NS) in the controls and 158 +/- 21 vs 166 +/- 23 mmHg (NS) in the coronary patients; DBP 97 +/- 10 vs 102 +/- 27 mmHg (NS) in the controls and 85 +/- 6 vs 90 +/- 10 mmHg (NS) in the coronary patients; O2 sat 96.8 +/- 1 vs 97.6 +/- 0.8% (p < 0.05) in the coronary patients. The anaerobic threshold and peak VO2 were much higher during exercise in the sitting position: oxygen consumption at the threshold 14.8 +/- 3.8 vs 12.6 +/- 2.3 ml.kg-1.min-1 (p < 0.01), peak VO2 22.2 +/- 5.9 vs 18.8 +/- 4.7 ml.kg-1.min-1 (p < 0.01) in the coronary patients. The results of this study show that the cardiovascular stimulation obtained in the decubitus position is not identical to that obtained by traditional exercise stress testing, particularly in coronary patients.

Plasma iron status and lipid peroxidation following thrombolytic therapy for acute myocardial infarction

Free radical species have been implicated as important agents involved in myocardial ischemic and reperfusion injuries. Superoxide is capable of mobilizing iron from ferritin and the released iron can cause hydroxyl formation from H2O2. The aim of this study was to evaluate the time-dependent increase in lipid peroxidation assessed by plasma thiobarbituric acid reactive substances (TBARS) and the relationship between lipid-peroxidation and the iron status. Peripheral venous blood samples were obtained from 17 men with acute myocardial infarction (AMI) before thrombolytic treatment (T0) and 1, 2, 3, 4, 8, 12, 16, 20, 24 and 48 hours after commencing fibrinolytic treatment. The concentration of TBARS, the parameters of iron metabolism, serum myoglobin, creatine kinase, and creatine kinase-MB were measured. Early reperfusion was judged by regression of sinus tachycardia (ST) elevation and reduction of chest pain. Recanalization of coronary artery was evaluated by a late coronary angiography 24-96 hours after thrombolysis. After thrombolytic therapy, the TBARS level was raised from 2.98 +/- 0.80 (T0) to 4.57 +/- 1.24 (peak), and decreased to 2.96 +/- 0.40 nmol/mL plasma at T48 (T0 vs peak: P < 0.001, peak vs T48: P < 0.001, T0 vs T48: NS). The mean time of the peak was observed at 9.7 +/- 7.5 hours. The iron increased significantly from 0.67 +/- 0.34 (T0) to 1.15 +/- 0.52 mg/L (peak), and returned to the pre-reperfusion to levels: 0.53 +/- 0.28 UI/L at T48 (TO vs peak: P < 0.001, peak vs T48: P < 0.001, T0 vs T48: NS). The mean time of the peak was observed at 9.4 +/- 7.3 hours. In return, no correlation was found between the increase of plasma creatine-kinase activity, myoglobin and iron or between the biochemical markers and time of fibrinolytic therapy. The results confirmed the importance of the temporal relationship between lipid peroxidation and iron status after thrombolytic therapy. Our results are in agreement with the concept that antioxidant agents used in association with thrombolytic therapy might be useful.

[Result and outcome of prenatal detection of congenital cardiopathies at the Côte-d'Or over a period of 9 years]

Antenatal echocardiographic diagnosis of congenital heart disease in 699 women living in the department of the Côte d'Or between 1988 and 1996 revealed 39 cardiac abnormalities which were later confirmed by anatomical examination or echocardiography. During the same period, 157 cardiac malformations which could have been detected in the antenatal period were diagnosed after birth. The detection rate of congenital heart disease was 19.8% over the whole study period, and 33.3% in the last three years. The malformations which were most easily diagnosed were hypoplastic left ventricle, single ventricle, atriventricular canal and severe obstruction of the ventricular outflow tracts. Twenty-one abortions (53.8%) were undertaken because of the severity of the cardiac lesion or of a genetic abnormality. Seventeen children were live born (43.5%) but, globally, they had severe malformations and the mortality rate was 84.5% whereas in the children diagnosed post-partum, the lesions were generally less severe and the mortality was 19.7%. The detection rate of congenital heart disease depends on the screening of first intention. Thus, 90% of the lesions diagnosed in this series were referred because of a foetal heart abnormality and, in this indication, echographic expertise was by far the most accurate with 33% of confirmation. As other workers have reported, teaching programmes and regional collaboration between physicians implicated in antenatal care are essential.